title: Structural and nanomechanical properties of BiFeO3 thin films deposited by radio frequency magnetron sputtering.
abstract: The nanomechanical properties of BiFeO3 (BFO) thin films are subjected to nanoindentation evaluation. BFO thin films are grown on the Pt/Ti/SiO2/Si substrates by using radio frequency magnetron sputtering with various deposition temperatures. The structure was analyzed by X-ray diffraction, and the results confirmed the presence of BFO phases. Atomic force microscopy revealed that the average film surface roughness increased with increasing of the deposition temperature. A Berkovich nanoindenter operated with the continuous contact stiffness measurement option indicated that the hardness decreases from 10.6 to 6.8 GPa for films deposited at 350°C and 450°C, respectively. In contrast, Young's modulus for the former is 170.8 GPa as compared to a value of 131.4 GPa for the latter. The relationship between the hardness and film grain size appears to follow closely with the Hall-Petch equation.
authors.affiliation: Department of Materials Science and Engineering, I-Shou University, Kaohsiung 840, Taiwan. srjian@isu.edu.tw.
authors.forename: Sheng-Rui
authors.initials: SR
authors.lastname: Jian
authors.forename: Huang-Wei
authors.initials: HW
authors.lastname: Chang
authors.forename: Yu-Chin
authors.initials: YC
authors.lastname: Tseng
authors.forename: Ping-Han
authors.initials: PH
authors.lastname: Chen
authors.forename: Jenh-Yih
authors.initials: JY
authors.lastname: Juang